Opioid-free anesthesia is a new approach to anesthesia, described and used for many years. If it represents many advantages by reducing the side effects of morphine, its precise place in current practice and in terms of postoperative rehabilitation remains to be determined. Studies are not yet numerous enough to affirm a real benefit.

Obese patients are potentially able to benefit from the reduction in the use of morphine during surgery, in terms of quality of postoperative analgesia, side effects (respiratory depression, ileus, somnolence) and early rehabilitation.

Inclusion criteria:

• Major subject (≥ 18 years old),
• who have undergone bariatric surgery at the HUS between January 01, 2017 and December 31, 2019
• Subject who has not expressed his or her opposition, after information, to the reuse of his or her data for the purpose of this research

Exclusion Criteria:

• Subject who has expressed his/her opposition to participate in the study
• Subjects under guardianship, curatorship or legal protection, pregnant women

Major subject (≥ 18 years old) who have undergone bariatric surgery at the HUS between January 01, 2017 and December 31, 2019